大黄试样经乙醇(6+4)溶液超声提取3次,每次20 min。以母核1,8-二羟基蒽醌为标样,在428 nm波长处,采用分光光度法测定其中总蒽醌的含量。在优化的试验条件下,1,8-二羟基蒽醌的质量浓度在50.0 mg·L-1以内与其吸光度呈线性关系。用此方法测定大黄中总蒽醌含量,所得平均提取率与回流提取法一致,加标回收率在99.7%~100.5%之间。

Sample of rhubarb was extracted thrice for 20 min each with ethanol-water (6+4) mixture solution ultrasonic ally. The content of total anthraquinones in the extract was determined by spectrophotometry using 1,8-dihydroxy-anthraquinone as standard sample at the wavelength of 428 nm. Under the optimum condition, linear relationship between values of absorbance and mass concentration of 1,8-dihydroxy-anthraquinone was kept in the range within 50.0 mg·L-1. The proposed method was applied to the determination of total anthraquinones in rhubarb; the average extraction rate obtained was in consistency with that obtained by reflux extraction method. Test for recovery was made by standard addition method, and values of recovery obtained were in the range of 99.7%-100.5%.